this post was submitted on 19 Jun 2024
25 points (96.3% liked)
xkcd
8781 readers
143 users here now
A community for a webcomic of romance, sarcasm, math, and language.
founded 1 year ago
MODERATORS
you are viewing a single comment's thread
view the rest of the comments
view the rest of the comments
Of course!
Another point I was getting as is that pure electric cars suffer from the same problem space rockets do: most of their weight is fuel.
Hence they are heavy, need a lot of raw material and manufacturing. Read: Expensive and bad for the environment, compared to a cheaper plug in hybrid.
And a tiny, 5 horsepower gasoline generator is hilarously efficient compared to a car engine. And dirt cheap, and weighs virtually nothing. There are technical reasons for this, but basically it's not even in the same league, and produces a fraction of the emissions as a full ICE car.
Maybe truth is they started talking about doing a car like that and by the time it was ready for production they ended up with a regular ICE car because they nearly doubled the HP of the generator every time the design got reviewed like you are doing now. Before long it will be a tiny 98 HP generator…
You really don't need 90hp. Coasting on the freeway takes less than 10hp, depending on how big of a block you drive, so as long as the average is around that, the generator can keep the battery charged forever, and the battery handles any surge in power you need. It's only a problem if you drive like a jerk, and floor it out of every light or speed down the highway at 100+mph, and do it long enough to drain the battery.
But the brilliant part is that you can design the generator motor for single, constant RPM. I can't emphasize how much easier and more efficient that makes everything, vs. having to engineer a huge power/rpm range that can handle a dynamic load.